The present invention relates to a disc player, particularly to a compatible disc player capable of recording information on or reproducing information from DVD (digital video disc) and CD (compact disc).
A conventional compatible disc player comprises a driving system (using a spindle motor) for rotatably driving an optical disc, a servo mechanism mounting an optical pickup, both of which are arranged independently from each other on a base frame of the player.
The servo mechanism is movably connected with two mutually parallel guide shafts arranged on the base frame in a manner such that the center of the optical pickup may move along a trace coincident with a straight line passing through the center of an optical disc mounted on a turntable.
The optical pickup (two-focus optical pickup) is mounted on the servo mechanism. A driving motor is provided for reciprocatingly driving the servo mechanism through a group of driving force transmitting gears.
The optical pickup is fabricated so that when in use a laser beam emitted from a laser diode is allowed to pass through an objective lens and converged on to an optical disc so as to record information on the disc. Further, the optical pickup is also fabricated so that when in use a laser beam is allowed to irradiate an optical disc, a light beam reflected from the optical disc is permitted to pass through the objective lens to arrive at a photo-detector provided within the optical pickup, so as to reproduce information previously recorded on the optical disc. However, to ensure proper information recording and reproducing, it is extremely important to perform adjustments (tangential adjustment and radial adjustment) on the optical axis of the optical pickup, corresponding to a possible inclination of the optical disc mounted on the turntable.
For the above reason, an automatic optical axis adjusting device having a step motor is used to adjust the optical axis of an optical pickup. In detail, an upper chassis is mounted on the base frame. Between the upper chassis and the base frame is provided an optical axis adjusting device having adjustment screws capable of raising and lowering end portions of the guide shafts by virtue of the step motor. In this way, it is possible to adjust the optical axis of an optical pickup by raising or lowering the end portions of the guide shafts.
However, there are at least the following problems associated with the above-discussed conventional compatible disc player. Namely, since the driving system, the servo mechanism, and the base frame are arranged independently from one another, it is difficult to manufacture the disc player compact in size. Moreover, due to the above-discussed structure of the conventional compatible disc player, there are too many parts and elements forming the player, resulting in a high cost in manufacturing a compatible disc player.